U.S. patent number 9,611,695 [Application Number 14/252,756] was granted by the patent office on 2017-04-04 for dual pipe drilling head with improved bearing retention structure.
This patent grant is currently assigned to The Charles Machine Works, Inc.. The grantee listed for this patent is The Charles Machine Works, Inc.. Invention is credited to Curtis Johnson, Greg L. Slaughter, Jr., Travis W. Woodson.
United States Patent |
9,611,695 |
Slaughter, Jr. , et
al. |
April 4, 2017 |
**Please see images for:
( Certificate of Correction ) ** |
Dual pipe drilling head with improved bearing retention
structure
Abstract
A downhole tool assembly for use in directional drilling
operations. The assembly has a housing, a chuck, a cutting tool, a
hub, and an elongate drive member. The housing has a spindle for
supporting the hub and chuck for rotation thereon. The chuck is
connected to the hub and has a non-circular interior surface and a
box for supporting a cutting tool for rotation with the chuck. The
elongate drive member is disposed within the housing, the hub, and
the chuck. The drive member is operatively connected to the inner
member of a dual-member drill string for rotation independently of
the housing. The drive member has a non-circular external surface
corresponding to the non-circular interior surface of the chuck.
The pin end of the drive is slidably receivable in connector free
torque-transmitting engagement with the interior surface of the
chuck to drive rotation of the cutting tool, chuck, and hub
independently of the housing.
Inventors: |
Slaughter, Jr.; Greg L. (Perry,
OK), Woodson; Travis W. (Orlando, OK), Johnson;
Curtis (Goltry, OK) |
Applicant: |
Name |
City |
State |
Country |
Type |
The Charles Machine Works, Inc. |
Perry |
OK |
US |
|
|
Assignee: |
The Charles Machine Works, Inc.
(Perry, OK)
|
Family
ID: |
51686012 |
Appl.
No.: |
14/252,756 |
Filed: |
April 14, 2014 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20140305709 A1 |
Oct 16, 2014 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
61811452 |
Apr 12, 2013 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B
7/002 (20130101); E21B 7/062 (20130101); E21B
7/046 (20130101) |
Current International
Class: |
E21B
7/06 (20060101); E21B 7/00 (20060101); E21B
7/04 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Coy; Nicole
Attorney, Agent or Firm: Tomlinson McKinstry, P.C.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of provisional patent
application Ser. No. 61/811,452, filed on Apr. 12, 2013, the entire
contents of which are incorporated herein by reference.
Claims
What is claimed is:
1. An assembly comprising: a hollow first member having opposed
first and second ends, the first end has a projecting spindle and
the second end is configured to engage an outer member of a drill
string; a drive member situated within the hollow first member for
rotation independent of the first member, having opposed first and
second ends, in which the first end projects from the spindle and
the second end is configured to engage an inner member of a drill
string; and a second member positioned over both the spindle and
the first end of the drive member, the second member being
connected to the drive member for rotation with the drive
member.
2. The assembly of claim 1, further comprising a retainer
positioned on the first member within the second member and
configured to limit longitudinal movement of the second member
relative the first member.
3. The assembly of claim 2, in which the retainer has a maximum
cross-sectional dimension that exceeds a minimum internal
cross-sectional dimension of the second member.
4. The assembly of claim 1, further comprising a cutting member
connected to the second member for rotation therewith.
5. The assembly of claim 1, in which the first end of the drive
member has a non-circular outer profile and the second member has a
non-circular inner profile that interlocks with the non-circular
outer profile of the drive member.
6. The assembly of claim 1, in which the spindle has a maximum
outer diameter that is smaller than a minimum inner diameter of the
second member.
7. The assembly of claim 6, in which the second member comprises a
hub connected to a chuck.
8. The assembly of claim 1 in which the second member has opposed
first and second ends and in which a seal housing is positioned
within the second end of the second member and mounted for rotation
about the spindle with the second member.
9. The assembly of claim 8, further comprising: a retainer
positioned on the first member within the second member and
configured to limit longitudinal movement of the second member
relative the first member; and a bearing assembly positioned within
the second member to engage the spindle and bound by the retainer
and the seal housing.
10. The assembly of claim 8, comprising a tool member positioned to
couple the seal housing and the first member for rotation
together.
11. The assembly of claim 1 comprising a pin positioned at the
first end of the drive member and configured to limit longitudinal
movement of the drive member relative the second member.
12. The assembly of claim 1 comprising a locating beacon supported
by the first member.
13. The assembly of claim 1, in which the first member has a
shoulder positioned to limit longitudinal movement of the second
member relative the first member.
14. A system comprising: a drill string having a first end and a
second end, comprising an outer drive train and an inner drive
train, the inner drive train rotates independent of the outer drive
train; a horizontal directional drilling machine operatively
engaged to the drill string at its first end; and the assembly of
claim 1 operatively engaged to the second end of the drill string
such that the first member is operatively connected to the outer
drive train and the second member is operatively connected to the
inner drive train.
15. The system of claim 14, further comprising a cutting member
connected to the second member for rotation therewith.
16. A kit, comprising: an elongate first member having opposed
first and second ends and an end-to-end hollow region, the second
end is configured for connection to an outer member of a drill
string and the first end forms a spindle having a maximum
cross-sectional dimension that is smaller than a cross-sectional
dimension of the second end; a drive member supported within the
hollow region of the first member for rotation independent of the
first member and having opposed first and second ends, in which the
first end projects from the spindle and the second end is coupled
to an inner member of a drill string; and a second member
positioned over the spindle and coupled to the first end of the
drive member for rotation with the drive member.
17. The kit of claim 16 further comprising a retainer supported by
the spindle within the second member and configured to limit
longitudinal movement of the second member relative the first
member.
18. The kit of claim 16, in which the second member comprises a hub
and a chuck fixed together end-to-end for rotation together and in
which the drive member projects from the hub into the chuck.
19. The kit of claim 18, in which the chuck is configured for
connection to a drill bit.
20. The kit of claim 19, in which an interior profile of the chuck
is configured to engage a polygonal outer profile of the drive
member to transmit torque from the drive member to the hub and the
drill bit.
21. The kit of claim 16, in which the second member has opposed
first and second ends, and in which the first end is configured for
connection to a drill bit and the second end is configured to
engage a shoulder of the first member.
22. The kit of claim 16, in which the second member has opposed
first and second ends, and in which the first end is configured for
connection to a drill bit and the second end is configured to
support a seal housing inside the second member for rotation
therewith.
23. The kit of claim 22, in which a bearing assembly is supported
inside the second member by the spindle and bound by the seal
housing and the retainer.
24. The kit of claim 16, in which the first member comprises a
beacon housing.
25. An adapter for securing a downhole tool to a dual-pipe drill
string, comprising: a rotatable inner drive system comprising: a
hollow first member configured to engage the downhole tool in a
rotationally locked relationship; an elongate rotatable drive
member configured to engage the inner pipe of the dual-pipe drill
string at one end and configured to engage the first inner member
in a rotationally locked relationship at or near its opposite end;
and an outer drive system, rotatable independently of the first
drive system, comprising: a rotatable second member configured to
engage the outer pipe of the dual-pipe drill string at one of its
ends in a rotationally locked relationship and having at its
opposite end a projecting spindle that extends within the first
member.
26. The adapter of claim 25 in which the second member has a
non-uniform cross-sectional profile along its length, with the
profile having its minimum dimension at the projecting spindle.
Description
FIELD
The present invention relates generally to the field of horizontal
directional drilling and specifically to tools used with dual-pipe
drilling systems.
SUMMARY
The present invention is directed to a horizontal directional
drilling system comprising a rotary drilling machine, a drill
string, a cutting tool, and a downhole tool assembly. The drill
string has a first end and a second end. The first end is
operatively connected to the rotary machine to drive rotation of
the drill string. The drill string comprises an outer member and an
inner member. The inner member is rotatable independently of the
outer member. The downhole tool assembly is operatively connected
to the second end of the drill string. The assembly comprises a
chuck, a hub, housing, and an elongate drive member. The chuck
supports the cutting tool to rotate the cutting tool and comprises
a non-circular interior surface. The hub is connected to the chuck
for rotation with the chuck. The housing comprises a spindle and is
operatively connected to the outer member of the drill string for
rotation with the outer member of the drill string. The elongate
drive member is disposed within the housing and operatively
connected to the inner member of the drill string at a first end
and comprises a non-circular exterior surface corresponding to the
non-circular interior surface of the chuck at the second end. The
drive member is slidably receivable in connector-free
torque-transmitting engagement with the non-circular interior
surface of the chuck to drive rotation of the cutting tool, chuck,
and hub independently of the housing.
The present invention is likewise directed to a downhole tool
assembly for use in directional drilling operations. The assembly
comprises a housing, a chuck, a hub, and a drive member. The
housing has a first end and a second end. The first end comprises a
connector for connecting the housing to an outer member of a drill
string. The second end comprises a spindle. The hub is supported
for rotation about the spindle. The chuck is connected to the hub
to transmit torque from the chuck to the hub. The chuck comprises a
geometrically-shaped internal surface and a box for supporting a
cutting tool therein. The elongate drive member is disposed within
the housing, the hub and the chuck and operatively connected to an
inner member of the drill string for rotation independently of the
housing and outer member of the drill string. The drive member has
a geometrically-shaped pin end. The pin end of the drive member is
slidably receivable in connector-free torque-transmitting
engagement with the geometrically-shaped interior surface of the
chuck to drive rotation of the cutting tool, chuck, and hub
independently of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is diagrammatic representation of a horizontal directional
drilling operation using the downhole tool of the present
invention.
FIG. 2 is an isometric view of the downhole tool of the present
invention showing a cutting tool connected to the end of the
tool.
FIG. 3 is an isometric, sectional view of the downhole tool of the
present invention with the cutting tool removed.
FIG. 4 is a close-up view of the portion of the tool within the
dashed box shown in FIG. 3.
FIG. 5A is a close-up section view of the bearing assembly shown in
FIG. 4.
FIG. 5B is an alternative embodiment of the seat housing and hub
shown in FIG. 5A.
FIG. 6 is a partial view of the tool shown in FIG. 2 showing the
hub and the housing in a close-up view.
FIG. 7 is a sectional view of the hub and housing shown in FIG.
6.
DESCRIPTION
Directional boring machines are used to drill holes underneath
roads and other obstructions for the installation of gas lines,
telephone and electrical cable and other utilities. In the past,
installing a gas line or electrical cable across, for example a
roadway, required excavation of a trench through which the utility
line was installed. After installation, the trench was backfilled
with appropriate material, such as sand or crushed rock, in a
series of stages. A layer of fill material was placed in the trench
and tamped down, either manually or with a mechanical tamping
device. This process was repeated until the trench was filled to a
level close to the surface. At this point, the surface of the
roadway would be resurfaced with gravel, asphalt, or concrete,
depending upon the particular circumstances.
The development of the horizontal directional drilling has largely
eliminated the need to trench across roads or other surface
structures. The horizontal directional drilling ("HDD") system 10
comprises a rotary drilling machine 12, a drill string 14, a
cutting tool 16, and a downhole tool assembly 18. The drill string
14 generally comprises a series of pipe sections joined end to end
at pipe joints. Horizontal directional drills may utilize single
member drill strings or dual-member drill strings to create the
desired borehole. Drilling machines that use dual-member drill
strings are generally considered "all terrain" machines because
they are capable of drilling through soft soil as well as rocks and
rocky soil. Dual-member drill strings comprise a plurality of
dual-member pipe sections. Each dual-member pipe section comprises
an inner member supported inside an outer member. The inner member
is generally rotatable independent of the outer member. The inner
member may be used to rotate the cutting tool 16 to excavate the
formation, and the outer member is selectively rotated to align a
steering mechanism to change the direction of the borehole while
the rotating bit continues to drill. One such system is described
in U.S. Pat. No. 5,490,569, entitled Directional Boring Head With
Deflection Shoe, the contents of which are incorporated herein by
reference. Suitable dual-member drill strings, for use in
horizontal directional drilling, are disclosed in U.S. patent
application Ser. No. 13/951,797 and U.S. Pat. No. RE38418, both
entitled Dual Member Pipe Joint For a Dual Member Drill String, the
contents of which are incorporated herein by reference.
One method to connect dual-member drill string pipe sections
together is by threading the inner members together and threading
the outer members together. Another method is to connect the outer
members using a threaded connection and connect the inner member
using a non-threaded connection. This may be done by forming the
ends of the inner members in a non-threaded geometric shape, such
that the geometric-shape of the box end of the inner member
corresponds with the geometric-shape of the pin end of a second
inner member. The pin end of the inner member may slide axially
into the box end of the second inner member to form a
connector-free, torque-transmitting connection.
Continuing with FIG. 1, the drill string has a first end 20 and a
second end 22. At the first end 20, the inner member and outer
member are both operatively connected to the rotary machine 12 to
drive rotation of the inner member and the outer member.
Accordingly, the rotary drilling machine may comprise an inner
drive to drive rotation of the inner members and the cutting tool
16 and an outer drive used to selectively rotate the outer member
to position a steering toot on the downhole tool assembly for
steering the cutting tool.
The drill string 14 passes through a borehole 24 as the downhole
tool 18 is advanced to an exit point. The drill string 14 may be
tubular and comprise a fluid passage not shown) that extends
between the first end 20 and the second end 22. The fluid passage
may be formed in the annular space between the outer member and the
inner member of the drill string 14 and may also comprise a passage
formed within the inner member. The cutting tool 16 may comprise a
drill bit or head configured for boring and typically includes an
ejection nozzle for water or drilling mud to assist in boring. The
drill bit may be a directional drill bit or a tri-cone drill bit.
Alternatively, the cutting tool may comprise a back reamer.
Turning now to FIGS. 2 and 3, the downhole tool 18 and cutting tool
16 are shown in greater detail. The cutting tool 16 shown in FIG. 2
is a drill bit generally referred to as a tri-cone bit. The bit 16
comprises three roller cones 26 rotatably mounted to a bit body 28.
The bit 16 is connected to the downhole tool assembly 18 and
rotates in response to rotation of an elongate drive member 30.
The drive member 30 may comprise a connector 31 (FIG. 3) at its
first end. The connector 31 operatively connects the drive member
30 to the inner member of the drill string. The connector 31 may
comprise slip fit connector box end having a non-circular or
geometric-shaped internal surface. The drive member 30 also
comprises a non-circular exterior surface 33 at its second end.
Continuing with FIGS. 2 and 3, the downhole tool assembly 18
comprises a chuck 32, a hub 34, and a housing 36. The chuck 32 is
connected to the cutting tool 16 to rotate the cutting tool and may
comprises a threaded box 35 to receive a threaded pin (not shown)
of the drill bit. Chuck 32 will be discussed in more detail with
reference to FIG. 4 hereinafter. The hub 34 is connected to the
chuck 32 for rotation with the chuck. The hub 34 and the chuck 32
may be threaded together, welded as shown in FIG. 3, or constructed
from a single piece.
The housing 36 is generally elongate and comprises a pin end 38, a
spindle 39, a beacon housing 40, and an offset sub 46 that includes
a steering shoe. The pin end 38 may be threaded for connecting the
housing to a correspondingly threaded box end of the outer member
of the dual member drill string. The beacon housing 40 is a chamber
formed within the housing for supporting downhole electronics such
as a beacon 41, also known as a "sonde," used to track and locate
the downhole tool assembly 18 and cutting tool 16 during boring
operations. The beacon housing 40 is generally offset from the
rotational axis of the housing 36 and comprises a cover 42 fastened
to the housing with fasteners 43. The cover 42 may also be fastened
with pins and tongue-in-groove slots. The housing 36 may also
comprise one or more elongate slots 44 cut in the side of the
housing. Slots 44 allow electromagnetic signals emitted from the
beacon 41 to escape through the steel housing 36.
A steering shoe 45 may be disposed on the side of the housing 36 in
a known position relative to the beacon housing 40. The steering
shoe 45 is formed by the connection of the housing 36 with the
offset sub 46 to form an angle between the longitudinal axis (not
shown) of the downhole tool 18 and the longitudinal axis (not
shown) of the drill string. The angle of offset is generally
between 0.5 and four (4) degrees. The steering shoe 45 provides a
reaction surface against the borehole to force the drill bit 16 in
the direction opposite the steering shoe. The housing 36 also
comprises a slot 48 formed at the downhole end of the housing 36
used for a purpose described hereinafter.
The hub 34 is supported on the spindle 39 for rotation about the
spindle. The hub 34 covers a bearing assembly 50. The bearing
assembly 50 facilitates rotation of the hub 34 and chuck 32 about
the spindle 39 and supports the load applied to the downhole tool
assembly by the thrust and rotation motors of the rotary drive
machine 12.
Turning now to FIG. 4, a close-up view of a portion of the downhole
tool assembly 18 within dashed box 52 (FIG. 3) is shown. FIG. 4
shows the housing 36, the hub 34, and chuck 32. As previously
discussed the chuck 32 may comprise a threaded box 35 to receive a
threaded pin (not shown) of the cutting tool 16 (FIG. 2) to support
the cutting tool 16 for rotation with the chuck. The chuck 32 may
be connected to the hub 34 at a weld and a press fit joint 54 or a
threaded connection. The chuck 32 comprises a non-circular interior
surface 56 corresponding to the non-circular exterior surface 58 of
the pin end of the drive member 30. The non-circular surface 58 of
the pin end of the drive member 30 is slidably receivable in
connector-free torque transmitting engagement with the non-circular
interior surface 56 of the chuck 32 to drive rotation of the
cutting tool 16, the chuck, and the hub 34 independently of the
housing 36. Non-circular surfaces 56 and 58 may be
geometrically-shaped. Such surfaces may be hexagonal, octagonal,
square, triangular, pentagonal, a Torx-style feature, splined, or
any other geometric shape capable of transmitting the desired
torque through the feature. Co-pending U.S. patent application Ser.
No. 13/951,797, the contents of which are incorporated fully
herein, describes several non-circular geometrically-shaped torque
transmitting surfaces usable in the present invention. A retaining
pin 60 may be inserted through a hole formed at the end of the
drive member 30. The retaining pin 60 limits axial movement of the
drive member 30 to the right in FIG. 4. Threading the cutting tool
16 (FIG. 2) into box 35 will limit movement of the drive member 30
to the left in FIG. 4.
The hub 34 covers a bearing assembly 50 and distributes thrust
forces received from the spindle 39 to the chuck 32 and cutting
tool. The bearing assembly 50 is disposed between the spindle 39
and the hub 34 to facilitate rotation of the components relative to
one another. A seal 62 and ring 64 are disposed proximate the
connection of the chuck 32 to the hub. The seal 62 helps to prevent
the migration of cutting spoils or fluids into the space between
the spindle 39 and the bearing assembly. Ring 64 maintains the
location of the spindle within the hub to help keep fluid passage
66 open during operation. Ring 64 acts as a replaceable wear
surface for the seal to wear against should the assembly become
worn and need the seal surfaces refurbished. The bearings and the
split ring collar 88 maintain the location of the spindle within
the hub by capturing the bearings on the spindle 39.
A seal housing 68 may be connected to the uphole end 70 of the hub
34 using a snap ring or locking rig. Alternatively, the seal
housing 68 may be threaded to the uphole end 70 of the hub 34. The
seal housing 68 comprises a seal 72 used to limit the intrusion of
drilling spoils, cuttings, and fluid into the space between the
bearing assembly 50 and the spindle 39. The seal housing 68 also
comprises a groove 73 accessible through the slot 48 formed in
housing 36.
During drilling operations drilling fluid is pumped through the
drill string 14 into the fluid passage 74 (FIG. 3) formed by the
annular space between the drive member 30 and the interior surface
of the housing 36. Referring to FIG. 4, fluid continues to flow
along the fluid path 74 to passage 66. Passage 66 conducts the
fluid to through a wall 76 formed in the chuck 32 having a
plurality of openings 90 (FIG. 5A) that direct the fluid into chuck
passages 78. Chuck passages 78 direct the fluid into the box 35 and
ultimately through nozzles or holes formed in the cutting tool 16
into the bore 24 (FIG. 1). Thus, the present invention provides a
"floating spindle" that does not require the cyclically bending
drive member 30 to carry the thrust or pulling loads applied by the
drive machine 12 through the outer members of the drill string. The
construction of the downhole tool and fluid paths described herein
also permit higher flow rates of fluid to the cutting tool 16
through the housing 36 than provided in previous downhole tool
assemblies.
Turning now to FIG. 5A, the hub 34, axle 39, and housing 36 are
shown in a detail sectional view. FIG. 5A illustrates how the hub
34 and chuck 32 are retained to prevent disengagement of the hub
and chuck from the drive member 30 and housing 36. The seal housing
68 is threaded into the hub 34. A set screw 83 may be threaded into
port 79 and engage seal housing 68 to limit rotation of the hub
relative to the seal housing. Threaded plug 84 is placed within
service port 82 to plug drilled hole 80. Set screw 83 may also be
used to plug drilled holes 80. Drilled holes 80 allow communication
of grease from grease port 86, across the bearing surfaces, through
passages 80 and out ports 82. A snap ring may be positioned within
the service port 82 to retain a plug 84 within the port as an
additional measure to limit the possibility of disengagement of the
seal housing 68 from the hub 34. Alternatively, a simple
friction-based set screw may also be used to prevent rotation
between the seal housing 68 and hub 34. Service port 86 may be
formed proximate a split ring clamping collar 88 and the bearing
assembly 50. The service ports described herein provide access to
the space between the axle 39 and the bearing surfaces to allow an
operator to perform maintenance on the assembly. FIG. 5A also shows
fluid passages 90 formed in a wall 76, which are in fluid
communication with fluid passages 66 and 78 (FIG. 4).
Turning now to FIG. 6 the exterior of the housing 36, hub 34 and
beacon housing door 42 are shown. FIG. 6, illustrates that slot 48
may be aligned with groove 73 under certain conditions.
Referring now to FIG. 5B, an alternative construction for retaining
the seal housing with the hub 34 is shown. In FIG. 5B, a wire 94 is
shown disposed in a groove 96 formed in the hub 34 opposite a
groove 98 formed in the seal housing. In operation, the wire
comprises a hook member that hooks to the receiving surfaces on the
seal housing and hub. As the seal housing and hub are threaded
together the wire 94 is placed into groove 96 and groove 98 about
the circumference of the seal housing 68 and the inner surface of
the hub 34. The use of wire 94 fastens the seal housing 68 to hub
34.
Referring again to FIG. 5A, to disassemble the hub 34 and seal
housing 68, the snap ring used to retain plug 84 is removed from
service port 82. The plug 84 is then removed from the service port
82 at the top of the assembly. Next, the set screw 85 in the
service port 82 at the bottom of the tool is removed. As shown in
FIG. 6, once the plugs 84 have been removed the groove 73 may be
aligned with the slot 48. A tool 92 (FIG. 7) may be inserted into
the slot 48 and used to engage the groove 73 in the seal housing
68. This allows the operator to disconnect the hub 34 from the seal
housing 68 to disassemble the downhole tool assembly.
Various modifications can be made in the design and operation of
the present invention without departing from the spirit thereof.
Thus, while the principle preferred construction and modes of
operation of the invention have been explained in what is now
considered to represent its best embodiments, which have been
illustrated and described, it should be understood that the
invention may be practiced otherwise than as specifically
illustrated and described.
* * * * *